To me this looks like a cross between a graduation outfit and a carpet.

Here is the official Description

A high body of jaconot muslin, with a lace frill, over which is a low one, formed of pink silk and trimmed with the same material; the upper part of the trimming is tastefully ornamented with bows of pink ribbon. Long loose sleeve, finished down the arm with bands and bows, to correspond with the trimming of the train; it is drawn tight at the wrist, and ornamented with a large pink bow. A superb French shawl is thrown carelessly over the shoulders. The hair is dressed very much off the forehead, and low on each side of the face. Head-dress, the Polish cap, which is uncommonly novel and pretty; it is composed of black velvet and ornamented with a silk tassel and gold band. Necklace, ear-rings, and cross, composed of gold and pearl. French watch, set with pearls. White kid gloves, and black Levantine sandals.Mrs. Gill, of Cork-street, Burlington Gardens, has favoured us with the original and elegantly fancied dresses given in our prints this month.